Hood for gas valves



May 3 1949. E. H. MUELLER 2,469,074

I HOOD FOR GAS VALVE I Filed Aug. 21, 1946 IN V EN TOR. E/vm H. Nue//ef Patented May 3, 1949 ES F FI CEF H061)A FOR GAS.' VIVES" Ervill Ht ltilelll",` G-o's'se fPiht'e, l Michl Application August 21, 1946, Serial No. f 692,038

This invention relatesto theigasappliance fin'- arro'r` it4 has to' dof particularlyY with' anplii ances' usedL in connection with` gas burners such; for example', as'a valve.

In' considering" the' invention; aA gas' valve may be visualized?. Such" a' valve" is conventionally employed for'tlie'di'sciiarge of gas" into a mixing' tub`e`-or"the dikeofab'urner. Suchvalv'es usually employ what isy termed" a' hood; which" is' screw threaded onto an extension of the va'lvebody. The'hood l'ia'sA4 a discharge'ioritceanda needle or pointedy element is" frequently' employed and which is carried by thewalife" body so 'tliaty by Aadi justing.; the "hood-'on itss'crew threads: the needle or pointed element and the discharge'ap'erture'are' relativelyshifted so that'z' a" proper discharge' ofl gas' through th'e'ori'ceiis" obtained; Thev needle' or` pointed element*l thusiuriction's as a device forA meteringthe orifice;

The sizel off'tl`1e'out1et'v orii'oe" in the hoo'd" is variable, andthis depends'largely upon numerous factors includingthe'type'vofl gas which isusedi For example,y in'` someA sections of the" country, manufactured gas is"used exclusively; in otherq sections' of vthe' country; natural gas iscemployed and'in some lsections o'ffthecount'ry; a* mixture of these'gasesisemployeu: Also; thegas pressure is a factor to'b'e considered'.X A- manufacturer; such as a manufacturer of gas'rangesmay; fori example; llavequite-a` supply" offvalve'ston ha'nd, but1 for one reason" orN another it develops* thatYr viril-"el the vaivess tiieiriselves'y are'- satisfa'ct'fnyA for" a particular Iot offranges: hoods-*are'needed*witli a di'iferentsize outlet aperture.- Accordinglyf; the manufacturer41 may* orderY a'y quantity of" which" are to beL put' onto th'efvalves* already on hand: These hoods may' beorderedrom"amanufa'cturer'entirelyi'differerit fronitleole-whofurl' nis'h'ed the valve; Asta I result, riiuch'kv difficulty 'isf encountered-1 in comiiining tileI floods andi the vaives' because Of^varying manufacturiiigt teler#- aneesf Even wherelth'e samef'manufacturerisupi pliesf the lhoodsv` as supplied the -valvej tolerancesthe live gas leaking therefrom* mayy becomeignite'd." Thisisea dangerous situation. If the fit is too tight, it may become too diiiicult or even impossible toproperly'a-'djustthe` hood on the valver- The general object of the presentinventioniisry to provide an improved construction which embodies an improved hood'whichwilltupon any valve? construction. Thus; azi number of" liood's on' thehood'. With a construction rr'iadei'nV ao'-` co'reaiice vvitii tire invention, adjustment of the' nood is very'4 easily made becauseY the hood does notl'become tight' upon its threads but neverthee less" there' isv a sealing agency whichiset's upa' rather uniform` friction' so' that the hood -will maintain itself in any adjustednposition': Moreover," this'element nia-kes a tight non-leaking t" to" 4prevent" leaking irrespective-oi" how'iloose the tl'i'r'e'adrs'pn the hoodmay fit' those onthebod'yi The invention is disclosed in' the accompany-ing drawings'wherein one structure for carrying out theirivention lis shown.

Fig.' l'isa" cross sectional-view takenthrougha'n" exemplary valve 'showing the' hood applied there-vto;

Fig." 2" is an'l enlargedi View of theY hoodf` witli a" portion thereof out away showing the sc-zalirigl ele-1i lliefl'it'y in; seCtiOI.

Fig: Sois'afurtherl enlarged' View illustrating the screw thread sealing joint.

InFig; 1f a conventional vali/e3 is illustrated` as2 having abodyl I`, arotatable valve' member 2 therein; Whichisturnable in* its seatbymea'n's of' a"steirrtV equippedwitn a handle 42 Thevalve2A Body' has'- athreaded inlet extension! 51' andJv al threadedf'outlet eXtensionfSwhile the valve 'meinte ber-1 2 is Aported as f at-vr T sovthat itrfma'y beturn'e'd to' open'th'eI Valveiofrthe oW= of gas therfethrougfl'ilr and? to close' the' valve. Ther` gas Whichi oW's' through* the: valveriiayv be aridi usually'fiisf dis?-I ohalrgedinto the lthroatoffam'iiier tube or the'i-likei offra? burner as 'iuustrateucinl dotted Alines-.ats 9:;

'Bhe-hood" is generally" illustrated' at l 51" andi' itf' is Soi-hollow construction .having -internal threads ITB? which'` are farrangedIl to" bei threaded? uponl the: external Itlire'ad'sil l4v ofthev outlet extension' ofi the? val'fve.J Th'e-'hood-lis: provided lwith an Foutlet aperituire'loi'n 'jetfape1`t'ure:v I 821 andth'e 4valvebodyI may;y ber equippedfwith a needle 'orl'poiht'edf memberl I9? The hoodi'ris-.provided-'With an` enlarged base. 20 which is usually?inftheffornr'of a hexagon thus providingalnut yformation forl the reception of al wrench sothfat itmayube'turned. Frequently, the*- va'lvesare:relatively;r concealed and it isl necesev to'. usev vai vwrench of. -some length -forv applica-f4 tion? tor thenut-Zin order to'turn thefho'od orifits threads to adjust. thecfjet aperture-'i8 relative'ftof ther"elaine-rit? I 9 to thus:Y obtain lthe-:desired action for!th@discharge` of'the Igasthrougih the jet eportA It'l willi-I- be` appreciated,` as` above pointed outa thatduey to-y the small -outletport' or jet' porti-I8* that some'pressurefis maintained withinithe hood andunless-there-isi af -goo'd t' between itlie screw t threadsfl andiH-someffgasimay escape.` Thisfis# afidingerous situation=forlvarious obviousreasons.:

also above,. ai ranger manufacturer, for' exarrinlez may; have ailarge number ofvalves-ori'ha-ndn and The new hood construction of the present invention, as indicated in Fig. 2, resides in providing an internal groove in the hood as illustrated at 23 and into this groove is placed a ring or washer of elastic or resilient characteristic. This ring or washer is shown at 24. The material of which the ring is made is subject to variation.'

Under some conditions where heat may be encountered, it should be of some material capable of resistingT the heat to which it would be subjected although it need not be of heat resisting material for installations where no particular heat will be encountered. A fibrous substance, such as a fibrous material, or a cork composition, may be employed. The resilience required is not excessive and, therefore, a fairly hard ber may be used. The position of the groove 23 and, therefore, the washer 2d, is preferably inwardly from the open end of the hood so as to leave intact what may be termed lead threads 25. For the purpose of facilitating assembly of the ring into the hood, the lead threads may and preferably are, partially removed as indicated. This increases the inside diameter at the location of the lead threads so that the washer may, with more ease, be assembled into its groove.

The interior diameter of the washer is preferably just about the same as the diameter measured across the inside of the hood from the apices of the threads l as illustrated in Fig. 2` In its original form the washer 2li ts fairly snugly in its groove so that it normally stands as a barrier between the lead threads 25 and the remaining threads Ii. The number of lead threads 25 is variable but for normal purposes it is thought that about two full threads will suffice. It might be said further that the exterior threads l1 on the valve body and the interior threads i6 in the hood are straight threads and so that the hood may be adjusted along the extension 6 throughout the length of the threads. In applying the hood to the threaded stem, the lead threads 25 are first engaged with the threads Il and the hood turned to advance the same on the threads H. As the threads l? reach the washer 24 the threads l1 impress themselves into the washer as illustrated in Fig. 3. The threads I7 preferably do not out a thread in the washer because of the tough elastic character of the e washer. The material of the washer is compressed as the shape of the threads are impressed into the same. This also tightens the washer in its groove. As the hood is continued to be threaded onto the stem, the washer turns with the hood and the threads H merely follow the impressed formation in the washer.

This construction provides an effective seal against leakage of gas. As a matter of fact, tests have been made under excessive pressures and no leakage was found. The hood turns on the stem with a nice, smooth friction action and the friction is suflicient to maintain the hood in any adjusted position. Thus, fairly large tolerances as between the internal threads I6 of the hood and the external threads l1 of the valve is permissible and, in fact, it is preferable that the hood should normally t loosely upon the extension 6 in order to obtain the full benefits of the sealing character and friction provisions of the washer. It also 4 has been found that a hood of this kind can be completely removed from the valve body numerous times and replaced thereon Without any deleterions effect upon the sealing and friction characteristics. This is due to several factors including these: The hood is always accurately piloted on 'the valve extension by the lead threads 25 before the threads i7 reach the washer; therefore, the formation of the threads l 'I is impressed into the washer at the same location upon each application. Also, the lead threads serve to advance the hood on the threads I7 with the result that the washer is not called upon to perform any function of advancing or retracting the hood axially is turned. In other words, the lead threads 25 take the initial axial thrust until such time as the remaining threads It or some of them are engaged by lthe threads I7 when the axial thrust is distributed through the various metal threads.`

A further factor is the fact that the threads I1 do not cut their shape into the Washer but merely impress the same as by compressing and compacting the material of the washer.

I claim:

1. In a gas appliance having a hollow part for the flow of gas and which part is provided with external threads, a hood of hollow formation provided with an outlet orice and having internal threads for engaging said external threads, said hood having an internal circumferential recess therein, said recess being positioned within the hood so that the internal threads have some of its convolutions in advance thereof which con stitute a lead thread, and an unthreaded washer of elastic or resilient characteristic situated in said groove and having an internal diameter such as to engage the external threads on the said hollow part whereby to establish frictional engagement of the hood with said hollow part and a sealed joint to prevent escape of gas, said lead threads being partially cut away to increase the internal diameter to facilitate assembly of the washer in its groove.

2. A hood for application to a hollow threaded member for the flow of gas comprising, a hollow body having an outlet orifice and having internal threads for engaging the threads of the hollow member, said hood having an internal circumferential recess formed therein at a location inwardly of one or more convolutions of the internal thread and an unthreaded washer of elastic or resilient characteristic positioned in the groove, said washer having an internal diameter less than the maximum outside diameter of the threads on the hollow member whereby to be engaged by said external threads as the hood is threaded onto the member to provide a gas seal and a frictional engagement between the hood and said hollow member, the lead threads in the hood which are outwardly 0f the washer having their tip portions removed to facilitate assembly of the washer in its groove. i

ERVIN H. MUELLER.

REFERENCES vCITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 350,796 Allender et al Oct. 12, 1886 `928,453 Jacobsr July 20, 1909 1,356,476 Schweinert Oct. 19, 1920 1,756,167 f Avery Apr. 29, 1930 

